Hydrologic Outlook issued March 02 at 12:42PM PST until March 08 at 3:00PM PST by NWS

Effective: Wednesday, March 2, 2016 at 12:42 p.m.

Expires: Tuesday, March 8, 2016 at 3 p.m.

SERIES OF STORM SYSTEMS TO ARRIVE IN CALIFORNIABEGINNING AS EARLY AS THURSDAY, MARCH 3, THE BAY AREA`S PREVIOUSMID-WINTER DRY SPELL WILL MAKE AN ABOUT-FACE INTO A PREDOMINANTLYWET PATTERN. RAINFALL ON THURSDAY WILL BE LIGHT, WITH ACCUMULATIONGENERALLY WELL LESS THAN AN INCH AND MOSTLY CONCENTRATED FROM THESANTA CRUZ MOUNTAINS NORTHWARD. BY FRIDAY MORNING ONLY THE SANTACRUZ MOUNTAIN AND THE COASTAL MOUNTAINS OF SONOMA COUNTY MAYRECEIVE RAINFALL IN EXCESS OF AN INCH. AGAIN, LIGHT RAIN ISEXPECTED THROUGH FRIDAY, BUT RAINFALL INTENSITY IS EXPECTED TOINCREASE IN THE OVERNIGHT HOURS. TOTALS FOR THE 24-HOUR PERIODBEGINNING FRIDAY AT 4AM LOCAL EXTENDING TO SATURDAY 4AM ARE LIKELYTO REACH 1-2 INCHES IN COASTAL MOUNTAINS THROUGHOUT THE SERVICEAREA, INCLUDING THE SANTA LUCIAS IN MONTEREY COUNTY. ACONTINUATION OF INTENSE RAIN WILL FOLLOW, WITH SEVERAL MORE INCHESFALLING OVER SATURDAY AND SUNDAY, AGAIN CONCENTRATED IN COASTALRANGES. SIX-DAY TOTALS, EXTENDING FROM WEDNESDAY MARCH 2 THROUGHEARLY TUESDAY MORNING, SHOULD YIELD 4-7 INCHES IN COASTALMOUNTAINS AND 1-3 INCHES IN VALLEY FLOORS AND INLAND AREAS.UNCERTAINTY REMAINS ON THE SPECIFICS OF WEATHER PATTERNS FOR NEXTWEEK. ALTHOUGH MOST MODELS AND FORECASTER INPUT SUGGEST CONTINUEDWET WEATHER THROUGH NEXT WEEK, THE EXACT TIMING, LOCATION, ANDAMOUNT REMAIN UNCERTAIN. WITH WET WEATHER EXPECTED FOR NEXT WEEK,FOLLOWING SEVERAL INCHES OF RAIN OVER THE WEEKEND, RAIN WILLLIKELY BE FALLING ON NEAR-SATURATED TO SATURATED SOILS. THUSWATERSHEDS WILL BE PRIMED TO QUICKLY CONVERT RAIN INTO RUNOFF ANDWILL ALSO HAVE THE POTENTIAL TO GENERATE DEBRIS FLOWS ANDLANDSLIDES IN SATURATED AREAS WHERE RAINFALL RATES EXCEED 1-INCHPER HOUR.IMPACTS ASSOCIATED WITH THE RAINFALL EXTENDING THROUGH THE WEEKENDWILL LIKELY BE LIMITED TO URBAN FLOODING IN AREAS WHERE STORMDRAINS BECOME CLOGGED OR OVERWHELMED BY RUNOFF DURING INTENSEBURSTS OF RAIN. LOW LYING AGRICULTURAL AREAS MAY ALSO EXPERIENCEPONDING AND RUNOFF MAY ENTER ROADWAYS ADJACENT TO POORLY DRAINEDFIELDS. THE EXTENT TO WHICH CREEKS MAY JUMP THEIR BANKS WILLLARGELY DEPEND ON THE INTENSITY OF RAINFALL: INTENSE BURSTSSEPARATED BY LIGHT RAIN OR REPRIEVES MAY PROVIDE INITIALLY DRYWATERSHEDS TO INFILTRATE RAINFALL AND CONTAIN RUNOFF WITHINCHANNELS. PROTRACTED INTENSE RAIN, WHICH IS POSSIBLE (AND APPEARSLIKELY OVER THE WEEKEND), MAY CAUSE SOME FAST RESPONDING BASINS TOFLOOD. EXAMPLES OF THIS TYPE OF BEHAVIOR ARE LIKELY TO OCCUR INVALLEY SETTINGS OF THE NORTH BAY, PARTICULARLY IN THE PETALUMABASIN, AND THE VALLEY FORD, BODEGA, AND BLOOMFIELD AREAS FED BYSTEMPLE CREEK, SALMON CREEK, AND THE ESTERO AMERICANO. THE LOWERLAGUNA DE SANTA ROSA MAY ALSO EXPERIENCE ROUTINE FLOODING ANDDRAINAGE IMPACTS. QUICK URBAN DRAINAGE IN THE SANTA CLARA VALLEYCREEKS THAT ORIGINATE IN THE SANTA CRUZ MOUNTAINS MAY ALSOEXPERIENCE PROBLEMS. NOTABLY, WE WILL BE WATCHING THE LOS GATOS-GUADALUPE BASIN CLOSELY, AS WELL AS UPPER LLAGAS, SARATOGA,STEVENS, PERMANENTE, AND OTHER INTERVENING LOCAL DRAINAGES.HOWEVER, MOST CREEKS AND RIVERS IN THE SERVICE AREA WILL REMAINBELOW FLOOD LEVELS, BASED ON THE EXPECTED RAINFALL RATES DESCRIBEDHERE. SHOULD RAINFALL FORECASTS INCREASE, THIS STORY MAY CHANGE,SO PLEASE STAY TUNED TO UPDATES FROM THE SAN FRANCISCO BAY AREANWS OFFICE.PLEASE STAY TUNED TO LOCAL MEDIA OUTLETS AND OUR OWN NWS SOCIALMEDIA ACCOUNTS AND WEB PAGE FOR ADDITIONAL AND UPDATED INFORMATIONPRECEDING AND DURING THE STORM. AND PLEASE STAY SAFE!